**Manchester United ground out a 1-0 win over the Philadelphia Union at Lincoln Financial Field thanks to a 75th minute strike from Gabriel Obertan.
The MLS's newest team, the Philadelphia Union, welcomed Manchester United and 44,000 fans to the Lincoln Financial Field, home of the NFL's Philadelphia Eagles.
United started the game with a mixture of youth and experience, but failed to gain control of the match in the first half, and had to wait until the 75th minute for Obertan to break the deadlock.
Paul Scholes pulled the strings for United in the opening ten minutes, repeatedly searching for Obertan on the right wing with a series of stunning diagonal balls.
The Frenchman provided the first threat of the game for Sir Alex Ferguson's side in the eighth minute, after good work from Danny Welbeck.
The young forward picked out Obertan at the far post with a delicate cross, only for the 21-year-old to hammer the ball wide of goal with a thunderous volley.
The initial signs were ominous for a Union side which has lost eight of the first 14 games of its inaugural MLS season.
However, the hard-working hosts fought their way back into the game, with 19-year-old Danny Mwanga a constant menace to United's defensive line.
After a narrow miss from Welbeck at one end on the half-hour mark, the Union almost scored the opening goal just two minutes late, with Mwanga again at the heart of the threat.
The young Union striker played an arching diagonal ball to Sebastien Le Toux in the United penalty area, who laid the ball off for Alejandro Moreno to shoot.
The Venezuelan's shot was well blocked by Jonny Evans, though, and United somehow survived the attack.
With the Union beginning to attack with real purpose, gaps emerged at the back for United's speedy forward line to exploit, and Welbeck very nearly did just that in the 35th minute.
Ryan Giggs and Fabio combined well on the left before the latter picked out Welbeck in space in the centre.
The 19-year-old looked certain to score when he shot low to the keeper's left, but Brad Knighton produced a tremendous save to somehow get a hand to the ball.
United's frustration began to show towards the end of the half, with Scholes receiving a yellow card for a trademark, clumsy challenge, before the Union again came close to breaking the deadlock after Mwanga released Le Toux clean through on goal, only for the Frenchman to drag his shot wide of the far post.
Ferguson bucked the trend of pre-season friendlies by refusing to make a change at half-time, while the Union made seven.
However, despite the massively changed personnel, the Union continued to ask questions of the United defence.
Mwanga again pulled the strings, sending substitute Nick Zimmerman free on the right, only for the American to see his shot flash wide of the post.
United could, and perhaps should, have had a penalty in the 65th minute, after Obertan was clearly obstructed in the area, but the Frenchman finally made the decisive breakthrough just 10 minutes later, clipping Welbeck's delicate through-ball under the body of Brian Perk, the onrushing goalkeeper.
United substitute Dimitar Berbatov almost doubled the lead four minutes later, thundering a fabulous shot-on-the-turn against the crossbar.
United saw one more penalty appeal fall on deaf ears in the 83rd minute, and held on for a hard-earned, but ultimately deserved 1-0 victory.
Philadelphia Union: Knighton; Fiscal, Arrieta, Califf, Harvey; Le Toux, Miglioranzi, Coudet, Fred; Moreno, and Mwanga1
Manchester United: Kuszczak; O'Shea, Evans, Brown, Fabio; Obertan, Scholes, Giggs, Cleverley; Macheda, and Welbeck